Roche will make a $10 million up-front payment to Inovio with development and commercial milestones of up to $412.5 million for an exclusive worldwide license to the drug candidates and exclusive use of Inovio's Cellectra electroporation technology for delivery of the vaccines. Roche also has an option to license additional vaccines for cancers.

INO-5150 is a dual-antigen synthetic DNA vaccine that targets prostate-specific membrane antigen and prostate-specific antigen. Monkeys vaccinated with the compound generated "strong and robust T-cell immune response," according to Inovio. Those responses were the highest generated by a PSA-based immunotherapy in animal studies, the company said.

"IN0-5150 will allow promising combination opportunities with the Roche portfolio, particularly with our emerging cancer immunotherapeutic molecules," Hy Levitsky, Roche head of cancer immunology experimental medicine, said in a statement.

Roche has no therapies for hepatitis B in development, according to its official pipeline.

Another experimental vaccine in the deal, INO-1800, generated strong T-cell and antibody responses that led to the elimination of targeted liver cells in mice. "Those results indicate this DNA vaccine's potential to treat hepatitis B infection and prevent further development of the infection into liver cancer in humans," Inovio said.

"Collaborating with the world's pre-eminent oncology development partner allows us to rapidly advance two of our promising near-clinical stage immunotherapy products from our product pipeline as we continue our Phase 2 lead product, VGX-3100," J. Joseph Kim, Inovio president and CEO, said in a statement.

Roche presented promising data on its cancer immunotherapy anti-PDL1 antibody RG7446 at the American Society of Clinical Oncology this year. The compound is designed to make cancer cells more vulnerable to the body's immune system.

Roche's biologics arm, Genentech, is working on a Phase 1 prostate cancer therapy, RG7450, which it licensed from Seattle Genetics. It's an antibody-drug conjugate made up of a humanized monoclonal antibody directed against STEAP-1, a membrane protein overexpressed in cancer.

Inovio also is working on is own VGX-3100, a therapeutic vaccine for human papilloma virus that the company says has generated "best-in-class T-cell responses in a Phase 1 study."